Question re: 12-volt battery, please?

If you receive a replacement, how do you know it was not charged by the store before they give it to you?

 

I'm just impressed that you actually own a DMM.

OK then, you'll call the store, ask for a replacement, and the manager will argue with you about whether the battery was impaired by being at 12.4V for a period no longer than 2 months. Then he'll give in and say the replacement will be available the next day.

They'll hook up the battery to a 10A charger, charge it up, then call you and say it is ready. You'll bring your DMM, measure voltage at 12.9V, and be happy. Then you get to install the new battery a second time and will become really good at that process.

 

snopes.com: Do Cement Floors Ruin Car Batteries?

Apparently way back in the day they used rubber casings for batterys and you could discharge a battery by setting it on a conductive surface. Guaranteed that no modern battery is made that way anymore.

And converse to your concrete in freezing temps example, here in the extreme south putting a battery on a cool concrete floor (say 75 degrees) might be better for it than putting it on a shelf in a 90+ degree room.

As to your prior post asking for updated values on my battery after normal use I'll be glad to grab some numbers tomorrow and update the thread afterwards. I'm not going to bother to get out the DMM, I'll just grab some numbers from the MFD since I have my prior readings to compare.

 

Ok thanks. That will at least give Julia some numbers for comparison.

 

I would be pi$$$$$ed too, Julia2001. H

 

Ok, I guess I owe a apology or something like that. I have been taught that "old wives tale" by more than one person who was older than I am - currently 56 and counting. I was not aware of the info on snopes.com concerning the difference's in the battery cases. All I can say is I am sorry that my information was not correct. I try very hard to post good information. I do appreciate it when someone can show me a new and better way.

With all that said, please disregard the information I posted concerning placing 12 volt batteries on concrete. I will leave that one up to the individual who is handling his or her battery.

Ron

 

Thank you for posting this, please refer to post #231 for my reply concerning the issue.

Ron

 

Hi dorunron:
I thought the same thing up to a couple years ago! Still put a block of wood down before I add the old battery when on concrete.. <grin> H

 

Hey, I even learned something there . I've heard that bit about concrete and batteries dozens of times and always wondered why. This thread prompted me to actually do the search and find out why/why not. Since uart already gave you the chiding I just went for the informative response. Honestly given the mood I was in I would have given you the nuetral tone even if uart hadn't chimed in.

 

Yeah don't worry about it Ron. We all get fooled by those "often repeated yet wrong" stories sometimes. I know that you usually give good information.

 

OK so on Mar 12th my results from the MFD were

12.5 ACC mode
12.25 IG-ON mode

Note the above figures are with load, that was literally seconds after reading the battery at 12.94v with a DMM (full charge after 18 hours on a smart charger).


Typical use of this car is 16 miles each way to/from work but it stopped at the library 2 miles from home so it's last trip before I measured it today was only 2 miles. It also sat a couple of hours before I checked it

on Aug 24th my results from MFD were

12.3 ACC mode
12.0 IG-ON mode

down .2 to .3 from the full charge but then the last trip was a short one. Not enough of a drop to worry me.

my factory installed battery didn't cause problems until the display check MFD reading got in to the low 11 / high 10 range. If this battery ever gets that low I'll just put it on the CTEK Multi US 3300 charger that I use by way of the cigarette lighter adapter (no need to open the hatch or hood, I just roll down the drivers window and run the DC cord to the dash and the AC cord to the wall socket)

Really the Gen II prius doesn't charge the 12v battery fast enough to handle short trips well. If you don't drive long trips just get a convenient setup like mine and charge the battery for a full day or two once every 3 or 6 months depending on how often you need a top up. Myself I haven't topped up this battery since I got it but if I get a closer job I might start doing so again or maybe I will when winter comes around. Either way I'm not worried about the quality of the battery, I'm worried about the anemic charging system in the Prius.

 

Unless you modified the 12V power outlet wiring to function when the car is IG-OFF, use of a charger via the 12V power outlet will do nothing for the 12V battery.

 

I have to assume the dealer or initial owner of the car modified it as in MY 2005 prius there is a 12V socket between the front seats that is switched and one under the dash that is always on.

They had satellite radio installed (I'm assuming that wasn't a standard item), and may have had the 12v wiring rerouted when that was done.

As to testing a cigarette 12v port it's rather easy to test with any 12v device like a cell phone charger (the phone will tell you if it is charging or not) but the CTEK also has enough status lights to let you know when it sees a load or not.

 

Hmmm. Now that I am at home and had some time to do some research, I really don't know what to believe. There is more than one explanation and opinion concerning concrete floors and batteries. Some say it's a myth, some say it isn't. Some say it is due to temperature differences, other's say no. Some say it simply about the old method of battery construction (wood/rubber enclosure's), other's say something totally different.

With all that said, I am going to stick to not placing my good batteries on concrete, or at least try to avoid "cold" concrete as those who discuss the temperature differences within the cells do state that the battery will discharge.

Source of multiple info concerning the myth of "don't put that battery on the concrete floor".

Google

It is a interesting topic and I think if those of you who are interested will take the time to read through the links on at least the first page of the google search, you will begin to become perplexed with the myth, old wives tale, or fact too.

Ron